23944EMD1 bearing: complete specifications & equivalents
The 23944EMD1 is a ISO 15 radial bearing sized 220 x 300 x 60 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 220 mm |
| Outer diameter D | 300 mm |
| Width B | 60 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass, machined (M1) |
| Basic dynamic load rating C | 789 kN |
| Basic static load rating C0 | 1260 kN |
| Fatigue load limit Pu | 79.4 kN |
| Limiting speed (mechanical) | 1400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 12500 g |
| Manufacturer designation | NTN 23944EMD1 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & 23900-series range
| Bore d | 8.661 in |
|---|---|
| Outer diameter D | 11.811 in |
| Width B | 2.362 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 40 mm |
| Smallest bore in 23900-series | 160 mm |
| Largest outer diameter in 23900-series | 1820 mm |
| Width range across 23900-series | 45–315 mm |
| Bore position in 23900-series (smallest first) | 6 of 38 |
| Bore above smallest 23900-series size | 60 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23944EMKD1 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23900-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 23944EMKD1 (K/K30 sleeve or tapered-seat mounting). Verify shaft arrangement. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 23944EMD1 model number is decoded
23944EMD1 belongs to the 23900 series of NTN spherical rollers and carries the ＊ ULTAGE new-generation mark in the 2203E table: self-aligning, high radial capacity, moderate axial load in either direction. The leading digits are the ISO 15 dimension series (23900 series); the bore code resolves to 220 mm (two-digit code ×5, with the 00–03 exception table), and 300 mm OD / 60 mm width follow the general plan. The 40.0 mm radial section over the 220 mm bore carries two roller rows; capacity per millimetre of bore is about 3.6 kN/mm, among the highest of rolling bearings for the ISO 15 envelope. Grease/oil ratio: the 1,400 r/min limiting value is .82 of the 1,700 r/min oil value; heavy 60 mm-wide cages run hot in churning grease, so quantity and groove supply both matter. Fit the cylindrical-bore 23944EMD1 with the inner ring heated (max 120 °C) for the shaft interference; the outer ring slides into the housing with its spherical seat able to pivot after seating.
Typical equipment & failure modes
Common applications
- cement-rotary-kiln support and trunnion rolls
- large SAG/ball-mill trunnion and pinion shafts
- heavy vibrating screens and grizzly feeders
- offshore and marine propulsion shaftlines
Known failure patterns
- raceway spalling at the roller ends when misalignment or deflection concentrates the line contact
- pressed EA cage fatigue under sustained vibration when minimum load is not maintained
- micro-pitting when the EHL film is thinner than the raceway composite roughness
- false brinelling on stopped machines exposed to screen or crusher vibration
- asymmetric wear on the two roller rows from sustained angular misalignment beyond the self-aligning range
Selection pitfalls — read before you substitute
- At 220 mm bore 23944EMD1 is normally mounted on adapter/withdrawal sleeves with hydraulic assistance; follow the NTN drive-up angle or oil-injection procedure — manual nut tightening cannot set the multi-tonne seating correctly.
- Never substitute 23944EMD1 by envelope alone: the 1260 kN C0 and 79.4 kN Pu are specific to the NTN EM machined-brass-cage execution, and vibrating duty depends heavily on cage identity.
- Oil relubrication toward 1,700 r/min needs drain and level design; flooding the 60 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The cylindrical-bore 23944EMD1 and its tapered-bore counterpart 23944EMKD1 share envelope and ratings but not mounting: do not order the K variant unless the drawing specifies a sleeve or tapered seat.
- The cylindrical-bore 23944EMD1 and its tapered-bore counterpart 23944EMKD1 share envelope and ratings but not mounting: do not order the K variant unless the drawing specifies a sleeve or tapered seat.
- The 789/1260 kN ratings, 79.4 kN Pu and 12500 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 23944EMD1 (EM machined-brass-cage/D1); another maker's same-envelope part revises internal geometry, so re-verify ratings and cage before substitution on vibrating or rated drives.
Frequently asked questions
What are the dimensions and catalogue data of 23944EMD1?
23944EMD1 is an NTN double-row spherical roller bearing to ISO 15: 220 mm bore, 300 mm OD and 60 mm width (8.661 × 11.811 × 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 789 kN, C0 1260 kN, Pu 79.4 kN, grease limiting speed 1,400 r/min, oil 1,700 r/min, mass about 12500 g. It is open, with one-piece machined brass cage (EM high-capacity design).
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
23944EMD1 has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 23944EMKD1 (K = 1:12, or K30 = 1:30 on the wide series), intended for adapter/withdrawal-sleeve mounting.
What do EA and EM mean on NTN spherical roller bearings?
EA is the NTN standard-capacity/high-capacity execution with a pressed sheet-steel window cage; EM is the high-capacity execution with a one-piece machined brass cage. Both use the optimised symmetric-roller design, but cage identity changes mass, speed behaviour and suitability for duties like vibrating screens, so they are separate order numbers. 23944EMD1 is the EM machined-brass-cage execution, listed with the ＊ ULTAGE new-generation mark.
What do D1 and W33 mean on 23944EMD1?
D1 is NTN's outer-ring lubrication feature: an annular groove with oil holes around the outer ring, aligned with a housing grease port so lubricant reaches both roller rows directly. 23944EMD1 carries D1; W33 is the equivalent industry-spelled annular-groove-and-holes feature seen on other executions.
How much misalignment and axial load can 23944EMD1 take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 23900 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 789 kN C / 1260 kN C0 — but sustained pure axial load is not recommended because it unloads one row.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.